The basic stenographic recording machine mechanism today used by court reporters has changed little since the invention of the machine over 40 years ago. Modern stenographic recording machines have adapted the basic mechanism to digital computer technology. However, despite the addition of such technology, the basic mechanical mechanism remains essentially intact with no innovations being made to address repetitive stress injuries that can result from frequent and prolonged use of such devices.
Frequent use of stenographic keyboards can result in injuries due to the unnatural angle the hands are required to assume to operate the keyboard of the existing stenographic recording machine when typing. An operator of a conventional stenographic keyboard must rotate his or her arms so as to dispose the hands in a palms-down position, by pronation, and align the fingers with the rows of keys by twisting each hand outwardly at the wrist, by ulnar deviation. Conventional stenographic keyboards can result in the operator's arm and hand muscles functioning poorly and increasing risks of injury. Tendons and nerves are adversely affected, and over time, this abuse can lead to repetitive stress injuries such as carpal tunnel syndrome. Symptoms of carpal tunnel syndrome are shooting pains from the wrists to the forearms, palms or fingers. In extreme cases, carpal tunnel syndrome is permanently debilitating. In a significant number of cases, repetitive stress injuries have forced court reporters and other workers which frequently use a stenographic keyboard to an alternative type of employment that does not require use of any keyboard.
This invention relates generally to ergonomic keyboard devices and more particularly to an ergonomic keyboard assembly that is arranged for providing input to a stenographic keyboard. The present invention allows an improved and more natural hand and arm position while typing, thereby reducing repetitive stress injuries such as carpal tunnel syndrome. To reduce the occurrence of carpal tunnel syndrome and other repetitive stress injuries, a keyboard should alleviate the underlying causes of repetitive stress injuries. Such an improved keyboard, which is realized in the present invention, relieves muscle and tendon strain, lessens or reduces wrist deviation, reduces or eliminates forearm pronation, reduces the distance fingers must travel and lessens the force necessary to the keys.
A number of prior art keyboard designs have been proposed in an attempt to reduce repetitive stress injuries. For example, U.S. Pat. No. 5,426,449 (Danziger) discloses an ergonomic keyboard featuring a front keypad facing the operator and left and right keypads that are at approximately a 45 degree angle positioned in tripod fashion substantially forming a pyramid with the front keypad. U.S. Pat. No. 5,017,030 (Crews) discloses an ergonomically designed keyboard usable on a typewriter or a compute terminal that is configured in accordance with ergonomic principles using chording of one thumb and one finger to type the characters of the English alphabet. The keyboard includes right and left pre-loaded palm pads which are shaped and contoured to fit the hands. The palm pads support the hands and operate the SHIFT and SHIFT LOCK functions. The punctuation keys are not affected by the SHIFT function. Movement of the writing position or cursor with respect to the medium is controlled by thumb-operated keys which are pushed in the direction of the desired movement. U.S. Pat. No. 4,661,005 (Lahr) discloses a design wherein the conventional QWERTY keyboard layout is split into two separate pieces allowing the operator to space each horizontal keypad at a comfortable interval. U. S. Pat. No. 4,579,470 (Casey) discloses a keyboard with keys concentrated in clusters in such a manner so as to be operated by specific fingers designated for specific clusters. Keys are clustered and clusters arranged to allow rapid finger motion with little hand motion. The keyboard arrangement also allows the hands and arms to be positioned in a natural manner in relation to the body. U.S. Pat. No. 4,244,659 (Malt) discloses a typewriter keyboard arranged to take into account the frequency of occurrence of letters so that the keys for the most frequently occurring letters are positioned for easiest operation by the typist. U. S. Pat. No. 3,945,482 (Einbinder) discloses orthogonal ten-finger keyboards for typewriters, computer terminals, and other devices processing alphanumeric information that maximize entry rates and stroking accuracy and minimizes finger motions and the time needed to master the keyboard.
While the aforementioned patents may be suitable for their intended purposes, the keyboards disclosed in these patents are arranged to replace existing keyboards that are utilized in conjunction with electric or electronic typewriters, word processors or computer input terminals. In other words, none are arranged for actuation of an existing keyboard device such as the mechanical keyboard utilized on a stenographic recording machine. It would be a significant advance in the art to provide an ergonomic keyboard that is arranged for providing input to an existing keyboard device such as a stenographic keyboard.